Corrugated nail making machine having a combined wire feeding and rolling means



RCK'RAN ACHINE HAVING ANS Feb. 4, 1958 J. c. (:0 2,821,727 CORRUGATED NA M A COMBINED 1 WIRE F ROLLING ME IL MAKING EEDING AND Filed May 16, 1955 4 Sheets-Shet 1 INVENTOR' (Jo/n1 Corc/r-rczn ATTORNEY Feb. 4, 1958 J. c. CORCKRAN CORRUGATED NAIL MAKING M HAV WIRE FEEDING AND R MEA Filed May 16, 1955 A COMBINED 4 Sheets-Sheet 2 INVENTOR ATTORNEY Feb. 4, 1958 J. c. CORCKRAN 2,321,727

r CORRUGATED NAIL MAKING MACHINE HAVING A COMBINED WIRE FEEDING AND ROLLING MEANS mu May 16,1955

4 Sheets-Sheet 3 INVENTOR 6/0/71? 6', C'o-rcfiram ATTORNE e 6 z W Feb. 4, 1958 J. c. CORCKRAN 2,321,727

CORRUGATED NAIL MAKING MACHINE HAVING A COMBINED WIRE FEEDING AND ROLLING MEANS Filed May 16, 1955 4 Sheets-Sheet 4 United States Patent O CORRUGATED NAIL MAKING MACHINE HAVING A COMBINED WIRE FEEDING AND ROLLING MEANS John C. Corckran, Baltimore, Md.

Application May 16, 1955, Serial No. 508,405

6 Claims. (Cl. -46) The present invention relates to a nail making machine and in particular to an improved feeding, forming and drawing mechanism for wire nail stock, and to a method of drawing and forming wire stock into a nail having four alternately parallel corrugated or serrated faces.

To form nails having continuous corrugations or serrations on the shank and further having four sides with the opposite sides parallel, the present invention provides a method whereby continuous round wire stock is drawn to a substantially square cross section and corrugations or serrations are formed in the flattened sides of the stock. Moreover this procedure, as another point of invention, is carried out in combination with the further step of heading the corrugated stock and cutting off a headed length with a pointed end into final nail form. By carrying out the successive steps progressively over the length of a continuous strand of wire stock, a nail of superior strength may be obtained in a manner economic with respect both to the number and cost of operations involved and to the life and cost of the tools required.

According to this method, round wire stock is flattened somewhat to form opposed parallel pairs of sides which pairs may be at right angles to each other; the two sides of one pair being further flattened and knurled simultaneously, and then the two sides of the other pair, to provide knurled stock of approximately square section; and finally the end length is cut off in a pointing operation with or without an intervening heading operation. By accomplishing simultaneously the progressive steps along successive parts of the stock, wire may be substantially squared and knurled at the same rate as it is consumed by the final step resulting in a finished nail. There is no need to coil intermediately formed stock and no bending takes place which might render the handling and guiding of the intermediate stock ditficult in the final nail forming operations.

By effecting the preliminary flattening and knurling through a rolling-drawing type operation, that tendency to develop a cast in the metal wire which is attendant upon die-drawing is avoided. Also with the wire drawn and rolled intermittently as it is consumed in the completion of successive nails, simplicity both in set up and maintenance of rolling operations is attained, while the intermittent rolling is accomplished without the disadvantageous heating of metal and rolls and roll wear which would occur in a continuous rolling of the stock at economic rates as a separate operation. It would be uneconomic to run continuously slowly enough to avoid heating.

This invention also provides a method of forming wire nails of the character referred to which may be carried out by a device which involves the changing of only certain parts of commonly used nail making machines, and infinite combinations of length and gauge, as well as the stock in the head can be made with the same attachment by proper adjustment.

The device is particularly designed to be carried upon a reciprocating carriage, or block which is positioned 2,321,727 Patented Feb. 4, 1958 adjacent the end of the machine into which the nail stock is fed. The present day nail making machines generally operate on the principle that the wire nail stock is fed into the machine at a predetermined time, after which it is clamped in a vise-like jaw for holding the stock in position while the nail head is formed. The machine is provided with a hammer to form the head on the inner end of the stock, after which the nail is cut from the stock the required length to complete the formation of the nail. The cut-off is in the form of a die which forms the point of the nail at the same time that it is cut oil. After the nail has been formed it is kicked out by an ejecting mechanism and the stock is fed again into the clamping die or vise and the process is repeated to form each nail. The stock is fed into the machine by a reciprocating carriage mounting a plurality of wire straightening rolls and also a suitable one way engaging chisel. The carriage obtains its motion from an eccentrically mounted reciprocating shaft attached to one end of a pivoted arm which has its other end connected to the carriage.

Another object of the invention is to provide a nail making machine which will change the circumferential contour of round nail stock and at the same time draw, or elongate the stock from which the nail is being made just prior to the time it is fed into position where the nail proper is formed.

Another object of the invention is to combine the stock surface forming means with the stock forwarding means, so that one set of means serves both purposes.

Another object of the invention is to provide mechanism that will knurl certain areas of the nail stock at the time the stock is being formed and drawn.

A further object of the invention is to provide such a device that may, with a minimum amount of modification of certain of the present nail making machines, be attached thereto.

While several objects of the invention have been pointed out other objects, uses and advantages will become apparent as the nature and mechanical structure of the device is more fully pointed out wh.ch consists in its novel construction, combination and arrangement of its several parts as described in the following detailed description and illustrated in the accompanying drawing, in which:

Figure 1 is a plan view in fine dotted lines of a conventional nail making machine showing the invention identified therewith in full lines.

Figure 2 is an enlarged plan view of that portion of the machine representing the invention as shown in Figure 1 in full lines.

Figure 3 is a side elevational view of the portion of the machine shown in Figure 2.

Figure 4 is a transverse sectional view in elevation taken on the line 44 of Figure 2.

Figure 5 is a similar sectional view taken on line 55 of Figure 2.

Figure 6 is a similar sectional view taken on line 6-6 of Figure 2.

Figure 7 is an enlarged fragmentary plan view of the wire nail stock showing the various stages of operations in their sequential order.

Figure 8 is a plan view similar to that shown in Figure 7 with the stock turned forty-five degrees showing one of the faces of the knurled stock.

Figure 9 is an enlarged sectional view of the circular or round wire nail stock material used with this invention.

Figure 10 is an enlarged fragmentary view in elevation of the initial forming rolls and the wire nail stockin section as it appears in the initial flattening operation.

Figure 11 is an enlarged fragmentary sectional view of the first set of knurling rolls and the approximate degree of the deformation of the wire nail stock at this station of the operation.

Figure 12 is an enlarged fragmentary sectional view of the second set of knurling rolls operating at a ninety degree angle to the plane of the first set of knurling rolls, showing the completion of the knurling operation.

Figure 13 is a greatly enlarged fragmentary view in elevation of the wire nail stock looking toward the left of the finished knurled portion in Figure 7.

Figure 14 is a view similar to Figure 13 looking toward the right of the finished knurled portion of Figure 7.

Figure 15 is a view similar to those shown in Figures 13 and 14 looking from an angle of forty-five degrees toward Figure 14.

Figure 16 is a view in elevation of two sides of a finished nail.

Figure 17 is a view similar to Figure 16 of the opposite two sides of the nail.

Figure 18 is an enlarged sectional view of the nail taken along the line 18-18 of Figure 17.

Figure 19 is a fragmentary front elevational view of the wire clamping vise, showing the wire in section.

Like reference characters are used to indicate like parts throughout the several views.

The improved device may be used on nail making machines similar to the one shown in the patent to Angell, No. 604,203, dated May 17. 1898.

The general outline of this type of nail making machine is shown in dotted lines in Figure l. The machine 1 is provided with a clamping vise 2 to engage the wire nail stock, a reciprocating hammer 3 for forming the nail head, and a nail cut-off die 4. The machine is operated by a rotatable shaft 5 which is adapted to reciprocate a shaft 6. One end of the shaft 6 is eccentrically mounted on the shaft 5 and the other end is connected to a rocker arm 7 which in turn is pivotally mounted upon a support 8 carried by the machine. The other end of the rocker arm is pivotally connected to a reciprocating carriage 9 upon which is mounted the drawing, forming and knurling rolls.

Figures 3 and 6 illustrate the connection of the rocker arm 7 to the reciprocating carriage 9, the propelling end of the arm preferably extending over the inner end of the carriage 9. Fixedly secured to the carriage is a pin 10. Over the upper end of the pin 10 is a block 11. The end of the arm 7 is provided with a longitudinally extending opening 7. The block 11 is adapted to fit rotatably over the pin 10 and slidably into opening 7 of the arm. The block is slidable in the opening 7' only longitudinally of the arm for the purpose of allowing the carriage to travel in a straight line, while being operated by the pivoted arm. The operation of the rocker arm 7 is in timed relationship with the other operating elements of the machine. The plan view of the carriage and the various elements of the improved device are in enlarged proportions. Extending along and fixed upon the upper surface of the carriage 9 are a plurality of forming, drawing and knurling rolls for preparing the wire nail stock for making the nail. The carriage 9 is fixedly attached to guide 9', slidable in extending Ways 12 carried by the base of the machine. The guide 9 is held in ways 12 by plate 12'.

The device of the present invention acts to feed the stock into the machine when the carriage is moved inwardly toward the machine and to form and draw the stock lengthwise and at the same time knurl its side surfaces when it is withdrawn; The clamping vise, the nail heading hammer, the cut-off and point forming die operate in the usual manner on the stock in forming the nail.

The wire nail stock 13 normally fed into the device is of circular cross-sectional form as shown in Figures 7, 8 and 9. The stock is fed into the device as indicated by the arrows in Figures 1 and 6. The stock comes first into contact with initial flattening rolls 14 and 15, which are illustrated as being in a horizontal plane.

The rolls 14 and 15 are rotatably mounted in brackets 16 and 17 by the pins 18 and 19. The relative distance between the brackets 16 and 17 may be regulated by the set screws 20 and 21. The brackets are kept in contact with the respective set screws by the compression spring 22, which is fixed between the adjacent edges of the brackets. The set screws and brackets are mounted in support 22" mounted on reciprocating carriage 9. These rolls 14 and 15 have grooved faces as shown in Figures 4 and 10. Each groove in each roll is of V-shape having sloping straight sides intersecting each other at an angle of substantially ninety degrees, the angle of the V-groove being at its center and the sides of the groove extending outwardly from a plane normal to the roll axis passing through that angle of the V-groove at substantially the same angle. When the stock is quite hard, or resilient, or otherwise resistant to change of formation, it has at times been found desirable to make the V-groove less than ninety degrees to more surely give the stock a ninety degree angle. The faces of the grooves in both rolls 14 and 15 are substantially alike as shown at 23, 24, 25 and 26 in Figure 10. These rolls 14 and 15 are so adjusted that they engage the round wire stock and compress it along four sides as shown at 27, 28, 29 and 30. Two of these sides are diametrically opposite each other as sides 27 and 30, and sides 28 and 29.

While these two rolls 14 and 15 are shown rotating in a horizontal plane, they may be rotated in any other convenient plane. It is to be noted that when the round wire stock passes through these rolls 14 and 15 the stock is pushed out in four directions between the flattening surfaces of the rolls and takes on a slightly square cross-sectional form, that is, it now has four narrow flat sides, as shown in Figures 7 and 8. This operation stretches the stock and guides it and prepares the surfaces for parallel faced knurling rolls, between which it keeps its straight course because originally flattened.

The first set of knurling rolls 31 and 32 engage the stock shortly after it has left the initial flattening rolls 14 and 15. These rolls are set to engage the stock along two of its flat surfaces and have their faces mounted in planes parallel to the surfaces 23 and 26 of the grooved rolls 14 and 15, that is, the face of the knurling roll 31 will engage the surface portion 27 of the stock, while the knurling roll 32 will engage the surface portion 30 of the stock. The distance between the faces of these knurling rolls 31 and 32 is substantially less than the distance between the surfaces 23 and 26 of the initial flattening rolls 14 and 15, and, therefore when the stock passes between these knurling rolls, it is further flattened and elongated and at the same time the surface over which the rolls pass is knurled, or corrugated. However, the rolls may have smooth faces and, therefore, would only function to flatten and draw the stock. Figure 11 illustrates the action of knurling rolls 31 and 32 on the stock. As the stock begins its travel through the knurling rolls 31 and 32, it has a general circumference as shown by the line 13', and after it has passed through the rolls it has a general circumference indicated by the line 13" which illustrates the amount the stock is flattened by this first set of knurling rolls.

The rolls 31 and 32 are carried within brackets 33 and 34 and are rotatably mounted therein on pins 35 and 36. The relative distance between the faces of the rolls is adjustable by the set screws 37 and 38. The brackets 33 and 34 are held in contact with the adjustable set screws by the compression spring 39 operating between the brackets. The brackets 33 and 34 are mounted within a frame 40 which in turn is mounted upon a support 41. The frame 40 is mounted upon the support 41 at an angle of forty-five degrees to the plane of the rolls 14-15, which is the correct position for these knurling rolls when the initial flattening rolls 14 and 15 are mounted in a horizontal plane, and the support 41 is mounted on the reciprocating carriage 9.

Also secured to the carriage 9 and adjacent the first set of knurling rolls 31 and 32, is a second set of knurling rolls 42 and 43. These rolls are arranged so that their faces are in parallel planes which are in turn perpendicular to the two parallel planes of the surfaces of the first two mentioned knurling rolls and are adapted to contact the initially flattened surfaces 29 and 28 of the stock 13. These rollers have preferably slightly more distance between their faces than the first two knurling rolls 31 and 32. As these rolls move along the stock, as shown in Figure 12, the extended portions 13" of the stcck are pressed inwardly. These rolls flatten and also draw the stock further and at the same time knurl the surfaces 29 and 28. Rolls 42 and 43 have their faces preferably spaced so that the final shape of the nail stock will have a substantially square cross-sectional form, as shown in Figure 18. However, these knurling rolls may be adjusted to modify this cross-sectional form if desired.

The rolls 42 and 43 are carried within brackets 44 and 45 and are preferably mounted therein on pins 46 and 47. The relative distance between the faces of the rolls is adjustable by the set screws 48 and 49. The brackets 44 and 45 are held in contact with the adjusting screws 48 and 49 by the compression spring 50 operating between the brackets. The brackets 44 and 45 are mounted within a frame 51-which in turn is mounted upon a support 52 at an angle of forty-five degrees to the plane of the initial flattening rolls 14 and 15 and at ninety degrees to the plane of the first mentioned knurling rolls 31 and 32, and the support 52 is mounted on the reciprocating carriage 9.

While in the preferred illustration the knurled stock is substantially of square cross-sectional form, the corner surface of the stock is rounded and without corrugations, the tops and bottoms of the corrugations being flat, the tops being continuous with the outer corner surfaces and the bottoms meeting those surfaces more angularly.

The stock is now ready to be formed into nails, the stock passing from the last set of knurling rolls 42 and 43 into the nail forming mechanism of the machine.

The jaws 2' of the clamping vise 2 which grip the stock preferably have opposed V-shaped notches extending lengthwise of the wire, the notches being aligned with the grooves of the initial flattening rolls 14 and 15 and the notches are also preferably internally diagonally corrugated to correspond to the corrugations of the corrugating rolls.

In operating the machine, the round wire stock, which is usually carried upon a reel, is set up opposite the end of the nail machine on which the forming and feeding device is located. The rolls are moved apart to allow the wire to be fed between the rolls to the clamping vise 2. The rolls are then closed by the roll adjusting screws until the proper location for the roll faces has been reached, and the machine is then started. Initially the clamping vise is fixed upon the wire stock when the carriage is at its innermost position toward the wire clamping vise 2. By rotating the shaft 5 the carriage is moved outwardly along the wire stock by the pivoted arm 7. As the wire is held by the clamping vise, the rolls 14 and 15 give the stock preliminary flat surfaces on four sides 27, 28, 29 and 30. The first set of knurling rolls 31 and 32 further flatten and knurl two of the opposite surfaces 27 and 30, and the second set of knurling rolls 42 and 43 flatten and knurl the two remaining surfaces 29 and 28. As the carriage reaches the end of its outward movement, the hammer 3 moves in on the end of the stock to form a head on the nail. At this point the clamping vise is released and the carriage is moved inwardly toward the machine carrying the stock forward through the clamping vise for the length of the nail to be formed, when the nail cut-off and point forming dies sever the stock at a predetermined point ahead of the clamping vise to complete the formation of the nail. The clamping vise again engages the stock adjacent the inner end thereof, and the carriage again moves outwardly to form, draw and knurl the round stock into the improved wire nail stock having a substantially square cross-section.

When the rolls on the carriage grip the wire to form it, they compress the wire, and since the wire is somewhat resilient, it expands after the rolls have moved over it, so that the rolls still have a moderately firm hold upon the wire to move it forward with the carriage. bhould the hold not be suflicient to move the wire forward, a chisel 53 may be provided. The chisel is fixed by set screw 54 in a slot in block 55 pivoted at 56 on the chisel base attached to the carriage 9. Block 55 has a projecting arm 57 held by spring 58 on arm 59 mounted on the chisel base on carriage 9, the spring holding the chisel against the wire. The chisel base on carriage 9 also carries a set screw 60 bearing against stop 61 on block 5:5 to limit the hold of the chisel upon the wire. The wire bears against an adjustable anvil 62 when held by the chisel.

As mentioned hereinbefore, the corners 63 of the finished nails as shown in Figures l6, l7 and 18 are not knurled or corrugated. This is also shown in Figures 12- 15 inclusive. it is also to be noted that the diameter 63, as shown in Figure 18, of the body of the nail from one opposite corner to the other is substantially that of the original diameter of the round stock. This too is apparent from an examination of Figures 9 and 12.

when using certain types of metals, such as copper, brass and aluminum, this operation, because of working the metal when straight, tends to increase its hardness and relieves both unbalanced surface tensions and internal stresses, or casts in the metal itself and reduces to a minimum any tendency of the nail to bend when driven.

In Figure 16 and also Figure 14, the corrugations 64 and 65 slant downwardly on two sides of the nail toward the same corner 66. The corrugations 67 and 68 on the opposite sides of the nail as shown in Figure 17 and also Figure 13, extend upwardly toward the same corner 69. the adjacent corrugations on the nail run in opposite directions when viewed from one corner and in the same direction when viewed from an adjacent corner. The corrugations on opposite parallel sides preferably have the same angle with respect to the nail length to evenly relieve unbalanced stress in the surface of the stock.

In Figures 13 to 17 inclusive, faces 68 and 65 are knurled by rolls 31 and 32 and faces 64 and 67 by rolls 42 and 43 respectively.

"these corrugations are adapted to engage the fibers of the wood which expand in the corrugation valleys to give the nail greatly increased holding ability, while the smooth, rounded corners allow the nail to be driven as easily into the wood as a round shank nail, with no tearing of the wood. The corners and merging tops of the corrugations act to keep the nail driving straight through the grain of the wood.

The wire stock from which the nail is made is preferably drawn and shaped by opposed rolls into substantially square cross-sectional form as described. However, this is not meant as a limitation as the drawing and changing of the cross-sectional contour of the stock by applying pressure to the outer surface to change its character by the pressure of a roll or rolls, whether corrugated or smooth with a die or the like by the return of the reciprocating carriage is considered within the scope of this invention.

The above described means and method, it will be noted, draw and roll forms the stock intermittently on the retracting movement of the carriage of the device shown, rather than by a continuous rolling and forming operation, so that there is opportunity for heat dissipation from roll faces and bearing surfaces. The movement of the entire carriage also favors heat transfer to the air. Roll life both with respect to the working faces and bearing surfaces is quite prolonged.

What is claimed as new and is desired to be secured by Letters Patent is:

1. In a nail making machine for forming corrugated sided nails from wire stock having a fixed heading and holding stock clamping vise for holding the wire stock in position in the machine, a reciprocating carriage unit carried on the machine and means for reciprocating the carriage unit for feeding stock to the clamping vise in forward movement, the clamping vise being released during such movement, in combination therewith and mounted on said carriage unit, at least two pairs of freely rotatable rolls with cylindrical faces having corrugations therein, the faces being parallel to the roll axes and the faces of the rolls of each pair being adjustably spaced from and substantially parallel to each other, and gripping the stock in passing it to the clamping vise, one pair of rolls being spaced forward of the other in the direction of wire feed and the axes of said pairs being angularly disposed relative to each other to successively flatten and corrugate different sides of the stock and change its cross-sectional form as it passes therethrough, each pair of rolls reducing the wire stock cross-section and extending its length when gripped in the clamping vise on reverse movement of the carriage unit.

2. In a machine as set forth in claim 1 including a first pair of rolls having faces provided with a V-shape groove, the sides of which are in planes disposed at substantially a ninety degree angle to each other, the respective groove sides on one roll being substantially parallel to those on the other at the points of wire contact to form initial flat surfaces alongfour sides of the stock to define surfaces of the stock over which the subsequent pairs of rolls pass, each roll of the subsequent pairs of rolls having a single face adapted to contact respectively opposite sides of the stock along two of the initially flattened sides of the stock for corrugating and further flattening the stock.

3. A Wire forming and feeding mechanism adapted to be carried adjacent the wire receiving end of a nail making machine having a fixed heading and holding stock clamping vise and a reciprocating carriage for feeding stock to the clamping vise in forward movement when the vise is released, comprising in combination therewith and mounted freely rotatably on said carriage, a plurality of pairs of oppositely spaced flattening and drawing rolls spaced from each other longitudinally of the direction of wire feed, the first pair of rolls each being provided with two angularly disposed faces, each being substantially parallel to the opposed faces on the other roll for initially flattening four sides of the stock, each subsequent pair having cylindrical faces with corrugations therein, the faces being parallel to the roll axes and those of each pair being spaced from each other in substantially parallel planes and the pairs being angularly disposed relative to each other to contact respectively opposite sides of the stock along two of the initially flattened sides of the stock, means for adjusting the pressure of the roll faces upon the said stock for flattening and corrugating the sides of the wire 6 stock and changing its cross-sectional form as it passes therethrough when gripped in the clamping vise and upon reverse movement of the carriage.

4. In a reciprocating feed for a nail making machine having a fixed wire nail heading and holding clamp and wire feeding reciprocating means for feeding nail stock to the clamp, while the clamp is released, on forward movement of the reciprocating means, in combination therewith and mounted freely rotatably on the reciprocating means, a wire entry guide comprising spaced opposed grooved rolls, the grooves having conical surfaces, the respective surfaces on one roll being substantially parallel with those on the other at the points of wire contact and between which the wire passes and is initially formed with opposed substantially parallel sides, a plurality of pairs of opposed cylindrically faced wire forming rolls, the faces being parallel to the roll axes and the axes of each pair being parallel, the opposed pairs being spaced from each other longitudinally of the direction of the wire feed to the clamp, the faces of the rolls of each pair having corrugations therein and being spaced from each other and means to vary the spacing, the axes of said pairs of rolls being angularly disposed relative to each other to contact their roll faces along two of the initially flattened sides of the wire for further flattening and also corrugating the sides of the wire, each pair of rolls reducing the wire cross-section and extending the length of the wire when held in the heading and holding clamp on reverse movement of the reciprocating means.

5. In a reciprocating feed for a nail making machine having a fixed wire nail heading and holding clamp and wire feeding reciprocating means for feeding nail stock to the clamp, while the clamp is released, on forward movement of the reciprocating means, in combination therewith and mounted freely rotatably on the reciprocating means, two pairs of opposed cylindrically faced wire forming rolls aligned with said clamp, the faces being parallel to the roll axes, and the axes of each pair being par allel, and the oposed pairs being spaced from each other longitudinally of the direction of the wire feed to the clamp, the faces of the rolls of each pair having corrugations therein and being spaced from each other and means to very the spacing, the axes of said pairs being angularly disposed relative to each other substantially ninety degrees, each pair of rolls corrugating the wire and reducing the wire cross-section and extending the length of the wire when held by the heading and holding clamp on reverse movement of the reciprocating means.

6. In a reciprocating feed as set forth in claim 5 in which the corrugations on the rolls of each opposed pair of rolls are parallel to each other and have similar angles with respect to the wire length at the points of wire contact.

References Cited in the file of this patent UNITED STATES PATENTS 383,328 Sweet May 22, 1888 457,237 Tyers Aug. 4, 1891 543,739 Perkins July 16, 1895 1,579,071 Braddock Mar. 30, 1926 2,244,852 Rendleman June 10, 1941 2,320,651 Poux June 1, 1943 FOREIGN PATENTS 243,396 Switzerland Dec. 16, 1946 

